Author Topic: Restoration Difficulty Level (Read 942752 times)

hkollan · « **Reply #450 on:** January 15, 2014, 11:11:55 »

Andy,

Quote

FYI Andy I think the green colour for brake pipes is the correct colour as supplied by Mercedes.

I think the brake lines look pretty good, the green color from Mercedes came years later on replacement lines.
Originally I think they where zinc or cad plated.

Hans

Garry · « **Reply #451 on:** January 16, 2014, 03:24:29 »

Andy,

Gong to be hot there tomorrow. Stay out of the shed.

Temp today driving back to home at lunchtime, 44.5 or 112f and expecting hotter tomorrow

andyburns · « **Reply #452 on:** January 16, 2014, 04:24:58 »

That's ridiculous Garry. You could literally fry an egg on the bonnet of the pagoda in those temps. Much cooler here today. Am enjoying a nice glass of red or three after returning to work. Haven't even given my 'precious' even a moments thought.

andyburns · « **Reply #453 on:** January 17, 2014, 08:02:24 »

BUMPER RESTO - PART 4

Back onto the Bead Blaster this afternoon. A bit of a marathon effort. 3 hours in total. Arms are burning a bit tonight.

Quite bizarre as the minute I started blasting the last of the chrome on the inside it started bubbling almost with the same appearance as paint with paint stripper on it. This allowed me to easily peel off the remaining chrome bringing the entire surface back to bare metal. As a result I should end up with a much better and more durable finish.

Need to pick up some more paint supplies tomorrow morning. Will hit it all with three coats of epoxy etch ready to finish off early next week with the right MB bumper shade. Before I get into the paint I will spend some more time on the sand paper dressing back any sharp edges and bit that I missed in the blaster. Am hopeful of a good result.

andyburns · « **Reply #454 on:** January 18, 2014, 02:20:42 »

BUMPER RESTO - PART 5

Climbed back into the job this morning. Spent 2 hours De-burring the edges of the bumpers with a die grinder. Just had to be careful I didn't go through all the existing layers of copper and nickel into the steel. A lot of the existing chrome didn't stand up to the die grinder and came flying off. I saw this as a good thing as it probably would have been a weak point and started to rust in years to come. Was aiming for the best possible substrate to put the new epoxy paint on. If I found rust under anything that came flying off I just kept on grinding until I hit solid material that was anchored well. Then took to the bumper iron with POR metal ready. Neutralizes any rust that I have missed and also coats the rest of the metal in with a coating of zinc. Just gotta make sure you wash off the residue after 10 minutes or you will end up with reactions with the primer.

andyburns · « **Reply #455 on:** January 18, 2014, 02:37:28 »

BUMPER RESTO - PART 6

Hit all the bumpers with POR metal ready as well. Then cleaned off with lashing of wax and grease remover before laying down three very thick coats of epoxy 2k primer. The primer filled quite a few of the rust divots and imperfections so once sanded back I should end up with a good final surface.

The same heat that caused my little 'black out' two days prior is now working in my favor as the garage has been turned into a mini bake oven. Its was to hot to paint in so I painted outside on a drop sheet. No wind so minimal chances of stuff blowing on the job. Once each part had received its dose it was moved back into the garage to cure. Normally I have to wait two days before you can sand. Even after 24 hours it feels quite soft to the touch but I am picking in this heat it will be good to good by tomorrow morning. Kinda academic as I dont have the paint for the final coat yet but will still be able to sand it out ready for the final push.

I also need to get all the bolts back in the bead blaster and off to the platers. I am tossing up to replace them all with stainless. It the lazy and easy was in my mind. I love putting back all the KMax original fasteners that came with the car. Every bolt you replace takes a little bit of history away from the car in my mind. Probably quite a crazy notion but one I have always lived by with all the refurbs I have undertaken in the past.

Hopefully I have preserved all this equipment long enough that the next generation will get to enjoy it. That the aim at the end of the day. What I have done with the bumpers isn't exactly what I would deem as beautiful work but should provide some long term protection.

If money wasn't an object I would get all the chrome chemically stripped and then bead blast and then re-chrome. Sort of made a rod for my own back with the way I have gone about these but at the end of the day I am certain I have saved more money which can be put toward other bits and pieces. I do feel a bit better about it all when I priced up a new set of OEM front and rear bumpers and new bumper irons at around 6k US. I would hate to write that cheque.

andyburns · « **Reply #456 on:** January 19, 2014, 09:21:16 »

BUMPER RESTO - PART 7

Spent this arvo sanding back the bumper irons and applying three coats of satin black. I dont think these are going to rust in a hurry again. Enough product to paint the Eiffel tower!

I am now worried that my average part count goal is going to slip. I dont think I will get time this week to get the bolts for the bumper blasted and plated, also I need to sort out the paint. Everything soaks the time.

I started on plan B to keep myself on target. The headlight I thought should be an easy candidate to go back in quickly. Carefully unwrapped my headlight units and to my total surprise found one of them to be almost brand spanking new. The other is in great condition as well with good shiny reflectors and no signs of the rust on the rear of the units which seems to be common place.

Just had to work on the earth points. More paint to carefully take off.

andyburns · « **Reply #457 on:** January 19, 2014, 09:23:45 »

More photos of the headlight earth point paint strip.

andyburns · « **Reply #458 on:** January 21, 2014, 04:39:14 »

Managed to get one of the head lamp assemblies back on tonight. Before the refit I bench tested all the bulbs and replaced a couple that were not working. Always worth the effort. Really starts to look nice when you put this stuff back on. Am really happy with all the headlamp notches. They all line up perfectly with the chrome.

One thing I did find is that the seal between the lamp and the headlight bucket didn't sit too well when screwed hard in. Not to bad, just a couple of mm in one place but enough to let water in and potentially start a rust problem at the bottom of the headlight bowl. Quite obviously Mercedes expected this as there are two drain holes at the base of the bowl. I would just prefer to keep it as dry as possible in any event. Its going to get wet at some point! More than likely in the foreseeable future only during grooming.

In any event I spent quite a while gluing an extra piece of 2mm closed cell foam onto the existing seal to give it a bit more of a weather tight teal. I have also replaced all the cheese head screws which hold the unit in with M8 318 Stainless equivalents. These little suckers all seem to rust so i think this is prudent. I also have had a rethink on the bumper bolts. The original K Max are so pitted on close inspection that I dont think they will have a new appearance when coated again. I went to pillage the ones from my part w108 and they have the same level of deterioration. I suppose they get more of a hammering than most other fasteners on the car. Perhaps the stainless option is the best solution for the bumpers. What do you guys think.

114015 · « **Reply #459 on:** January 22, 2014, 00:03:47 »

Quote

Perhaps the stainless option is the best solution for the bumpers. What do you guys think.

Hello Andy,
Yes, I think so too.

When I got my car many years ago I thought I'd 'replace all fasteners by stainless steel ones and you are fine' circumventing this stupid rust problem with many of the old ones.

Nevertheless it became quickly clear that most of the screws, bolts, nuts, fasteners on our cars (and on cars in general) must not be stainless steel but must keep their original property class (8.8, 10.9 or 12.9 in our cases) and cannot be substituted by A2-70 or so !!

With the bumper screws and (I think) all types of sheet-metals screws this is certainly different. Most of those can be replaced by A2-70 for better durability on our cars.
On most of these non-important non-torqued screws I use wax, grease or oil during reassembly as well.

The bolts for the (especially front) bumpers are always heavily rusty. I got them yellow zink plated again, but of course those still look odd and old.
New ones from the hardware shop are an alternative, especially after yellow zink (or cad) plating. But those are often no longer made by Kamax or NSF or Verbus or whatever the old ones were.
You can also buy new ones from MB ....
... but I really think the non-visible non-important torque, non-property class-important fasteners (like bumper screws) can be replaced by stainless steel ones...

Just my 2 cents...

Achim
(M8 wrench size 14 screws collector)

andyburns · « **Reply #460 on:** January 22, 2014, 05:58:13 »

BUMPER RESTO - PART 8

Achim, have taken your advice and gone stainless. In hindsight it was absolutely the right thing for the bumpers. From a cost, time and durability aspect I am a winner on this one. Total cost for all the mounting hardware in stainless a poultry 16 dollars US. The cost to have them replated alone, let alone the labor cost to have them bead blasted, would have exceeded this by 40 dollars. Its sooooo nice to just walk in to a shop and buy some of this stuff.... occasionally.

Also stopped at the painters to get some DB158 mixed up to finish off the bumpers and hub caps. While I was there he gave me a good tip. The paint he mixed was a 1k solid base coat tinted to suit. Normally you just mix it with a bit of thinners and blow it on. He suggested that I mix it with normal harder to give it much better durability and resistance to solvents. Also takes a little bit of gloss off and looks a bit more factory. He took one look at the finish on the back of my factory hub cap and insisted I use it replicate the factory look and feel. Mix ratio was 5 to 1. Apparently its a really common trick with painters. Trusted him and went ahead with it. No strange reaction and the result looks really good.

Spent another 2 hours sanding out the epoxy primer. I deliberately heaved it on really thick to fill some of the rust pit imperfections. Not the easiest way to do it as expoxy primer is really hard to sand. I could have used a high build primer but wanted a really solid protection barrier to stop the rust coming back. I managed to sand out at least 80-90% of all the imperfections. Quite happy with the result and well worth the effort.

Just have to wait for the bits to dry and get into the assembly. Hopefully I will be able to get on the right side of my goal to install one piece per day. That was about a week ago and I have only managed to fix up one headlight. I am counting the bumpers as 8 pieces.

andyburns · « **Reply #461 on:** January 22, 2014, 06:22:26 »

Also managed to mount up the remaining headlamp. Brought all new stainless cheese block head screws to keep it in place. Awesome to have both of these off the floor and better protected back in place on the car. The RHD headlight lens in particular are simply not available.. anywhere! Again I am really happy with the alignment of the notches. Great to have her eyes back on again!.

With all the paint that I had applied the threads for the bumpers had got fairly clogged up again. I ran a tap through them all and got the new stainless bolts gliding in the threads. Everything in place to refit the bumpers tomorrow after work.

Garry · « **Reply #462 on:** January 22, 2014, 11:08:42 »

Andy,

The bolts (and washers) for the front Bumper irons should be cad plated. If they are zinc plated now, which they appear to be, you could just dip them in a chromate to colour them up.

Garry

andyburns · « **Reply #463 on:** January 22, 2014, 19:01:30 »

Hey Garry, I think you have just been looking at the pictures and not reading my posts :'( Perhaps I should have listened to my instincts and not put so too much mundane babbel about the bumpers! Reading back over what I have post I actaully dont blame ya. It made me yawn a bit reading it. But the guts of what I have been going on about over the past couple of days is debating using stainless bolts or getting my old kmax redone. Went with the stainless option after having a good chin wag with Achim.

Garry · « **Reply #464 on:** January 22, 2014, 21:25:17 »

Your right, I missed the bit about walking in and buying off the shelf. Was so taken by the repainting of the rear of the bumpers that i was thinking of taking mine off and doing them properly.

Garry

andyburns · « **Reply #465 on:** January 22, 2014, 21:52:18 »

Garry... your far too kind.

114015 · « **Reply #466 on:** January 22, 2014, 22:23:38 »

Hallo Andy,

one more little hint ...
Put the brackets on the bumpers first and then mount the whole assembly onto the car, not the other way around.
It's too hard to access the screws for the bumper halves once you have the bracket already mounted on the car.... especially for the rear ones.

Quote

The bolts (and washers) for the front Bumper irons should be cad plated. If they are zinc plated now, which they appear to be, you could just dip them in a chromate to colour them up.

Garry,
That would definitely be a great thing, yellow cad plating of stainless steel bolts...

(Yes, I know that was not your suggestion here).

I was once told that is not possible but I don't know for sure.
Probably gold plating (different process, not electro-plating) could be an alternative here

Certainly a bit expensive but at least it looks somehow right ... from a little distance at least.

All best, and please keep on reporting, Andy!
I love it!

Achim

andyburns · « **Reply #467 on:** January 22, 2014, 22:45:29 »

Hi Achim,

Thanks for your tip. I had already discovered that when I bolted the brackets up to the bumpers just to test fit them but as of last night. They were taken off and bolted firmly to the bumper ready for the fit up tonight.

I have a small issue with some of the stainless bolts being every so slightly to long and either I grind them down or go back and get some 5mm shorter. The good thing about stainless is there is no coating and if you grind into the material you dont destroy the rust proofing.

Tomnistuff · « **Reply #468 on:** January 23, 2014, 00:27:05 »

CAD plating stainless is possible. It's simply necessary to separate them out from the non-stainless parts and identify them to the CAD plater (I used a magnet). The plater gives them some sort of pre-treatment before CAD plating - I don't remember which. I think it's an acid dip. It didn't even cost me extra at Detray Plating in Missouri. I had several pounds of stainless parts CAD plated for appearance purposes along with all the other parts (60 pounds total for about $475 plus shipping). Although under severe use, the CAD will wear off someday, at least the bolts won't rust when it does As previously mentioned, just watch out for the strength requirements in the applications where you plan to use stainless.

Tom Kizer

andyburns · « **Reply #469 on:** January 23, 2014, 00:34:13 »

Cheers Tom, Given these bolts are hidden in the bowels of the bumpers and not visible without an inspection mirror and torch when the bumpers are back on the car I have elected to go stainless. I dont think the strenght aspect will come into it with the bumpers. If I have a high speed accident the bumpers wont provide much protection and I am perfectly happy if the bolts shears and the bumpers fall off.

I do here what you say. I wouldn't use these for fasteners for the subframe or any other structural components without a whole bunch of research.

Tomnistuff · « **Reply #470 on:** January 23, 2014, 00:58:29 »

I am not proposing that the stainless fasteners should be CAD plated. I bought mostly stainless fasteners to replace those too far gone to replate with CAD. I figured that if the fastener is in a place where it's going to rust even with CAD plating, I might as well buy stainless. I only decided to CAD plate the stainless fasteners when I found out from Detray Plating that there is no extra charge to CAD plate stainless. It's as inexpensive as all the other fasteners, so why not?
I had planned to do what you did before I found that out, and still would have if it had been extra cost. I've still got some stainless fasteners in the car that are supposed to be chromed or CAD plated. Maybe it will give the experts something to argue about. If they notice that, maybe they won't notice something else that's wrong that's more important. In most cases, because I'm chasing you in my restoration, I come here to see what I'm supposed to do tomorrow or next week Rarely will I have already done something when you get around to doing it. Keep up the excellent work and documentation.
Tom Kizer

andyburns · « **Reply #471 on:** January 23, 2014, 08:15:08 »

BUMPER RESTO - PART 9

Mounted up all my irons to the rear bumpers this afternoon and then mounted them onto the car. Quite exciting to see another major chrome body up against the fresh silver paint. I think its a great combination. Quite happy with the result and even though its not perfect it looks good when you crawl under the car and look back up. It would have done my head in to have just mounted the rusty old versions up. Sure I would have lost sleep in years to come.

andyburns · « **Reply #472 on:** January 23, 2014, 08:22:44 »

BUMPER RESTO - PART 10

I was going to give up for the night and leave the front bumper till tomorrow. Figure I am on the good side of the ledger now in regard to my 'one part per day' policy.

Wife got a little grumpy at me so I decided to stay in the garage and assemble the front bumper. I had purchased new stainless coach bolts which hold the bumper together. I discovered that the dome head on them sat to high and interfered with thin chromed cover that hides up the join of the two halves and the fixing coach bolts.

Only solution was to take to them with the grinder. Stainless is an absolute mongrel to grind or cut. Very very hard. Took a good 10 minutes to carefully whittle down each one on the bench grinder. If they were steel it would be done in 15 seconds.

With a bit of trial and error I managed to get everything to bolt up and look right. A bit of patience here is the order of the day.

andyburns · « **Reply #473 on:** January 23, 2014, 08:39:37 »

BUMPER RESTO - PART 11 THE FINAL FRONTIER

Not that I am suggesting that I have been where no man has been before... just that it feels like it as its been such a drawn out arduous, dirty, back breaking job that no sensible man would follow in my foot steps. Probably the worst job of the resto so far to be honest. My advice for anyone else attempting this would be to have the bumpers stripped properly and start again from scorched earth. Even though I am happy with the result I have made a whip for my own back... and then used it on myself.

All this said I just couldn't wait till tomorrow to see the front bumper back on the car. The job probably should be undertaken with at least two people, perhaps even three to ensure no paint parts company with the car. Probably quite stupid to attempt it on your own.

I am quite glad I still have at least 10kg of clean rags as these came in essential to doing this job on your own. I pretty much wrapped the entire bumper and used masking tape to hold it all in place. Then very carefully used the trolley jack to edge up one side while lying flat on my back holding and guiding the other end. The adhoc technique worked and I managed, one by one, to do up the four bolts that hold the bumper to the iron. With the front bumper I mounted the irons to the car and then the bumper to the irons. The rear was done by mounting the iron to the bumper and then the iron to the car.

Any way I am now clear of the bumper project and am looking for my next target. Will sleep on that one.

Again I hope you guys haven't been bored to tears with this section. I know you all say you haven't but I am putting that down to the fact that most pagoda drivers are true gentlemen.

Garry · « **Reply #474 on:** January 23, 2014, 09:00:08 »

They look fantastic Andy.

Please keep the story going, it is great to read and gives me things to check as you go through the items.

Garry

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Author Topic: Restoration Difficulty Level (Read 942752 times)